Minimally invasive parathyroidectomy: how effective is preoperative sestamibi scanning?

Minimally invasive parathyroidectomy (MIP) guided by preoperative sestamibi scanning has been shown to reduce operative time, hospital stay, and cost in treating primary hyperparathyroidism. However, controversy exists over routine preoperative sestamibi scanning. The purpose of this study was to determine the utility of sestamibi scanning at our institution as part of the MIP protocol and to analyze calcium and parathyroid hormone levels as possible predictors of successful sestamibi scanning. Charts of 37 consecutive patients undergoing MIP at our institution were reviewed, and age, sex, preoperative calcium, and parathyroid (PTH) levels, invasiveness of procedure, and pathologic diagnosis were recorded. Sestamibi scans were reviewed and scored by 4 nuclear medicine faculty based on the level of suspicion for parathyroid adenoma. Neither calcium nor PTH correlated significantly with sestamibi scan score (Spearman coefficient, r = 0.075, P = 0.67 and r = 0.277, P = 0.10, respectively). Receiver-operating-characteristic (ROC) analysis showed sestamibi scanning to have sensitivity and specificity in predicting MIP completion (87% and 68%). Logistic regression showed only sestamibi scan (P = 0.038), not calcium or PTH (P = 0.977 and P = 0.767) to be predictive of MIP completion. In conclusion, sestamibi scanning effectively predicted the ability to perform MIP. However, preoperative calcium and PTH predicted neither sestamibi scan results nor completion of MIP.